Unimin Corporation of New Canaan, Conn. is a leading source of mined raw nepheline syenite, which is a natural occurring rock formed from several minerals and is found in deposits in only limited areas of the world. The nepheline syenite industry has developed technology that is used for grinding and crushing raw nepheline syenite rock and then converting the particulated nepheline syenite into usable fine grain powder. Thus, the field to which the present invention is directed is the industry of nepheline syenite and the technology of converting nepheline syenite as mined into usable form that is a commercial powder. In about 2001, Unimin Corporation, after substantial research and development, invented an ultra-fine nepheline syenite powder, which powder was believed to be the smallest commercially available and economically producible nepheline syenite powder. This ultra-fine powder had a maximum particle or grain size D99 substantially above 20 microns. However, it was classified as “ultra-fine” nepheline syenite powder because it had a maximum particle size of less than about 20 microns. Such “ultra-fine” nepheline syenite powder had the smallest commercially available grain size. At about this time, Unimin Corporation invented a nepheline syenite powder that had a maximum particle size of about 20 microns and a minimum particle size of less than 1-2 microns, which was caused by a removal of very small particles or fines. This powder was developed as an anti-blocking agent and was sold under the trademark MINBLOC HC1400. The particle size distribution of MINBLOC HC1400 was over 15 microns between the D95 and D5 particle sizes, as shown in FIGS. 14 and 15. Such anti-blocking agent and other nepheline syenite powders designated as “ultra-fine” and having only a controlled maximum particle size were the prior art nepheline syenite powder closest to the ultra-fine powder of the present invention.